News that Google will soon begin tracking users across most of its popular services, including Gmail and YouTube, was met with criticism and privacy concerns when the company unveiled a new policy Tuesday.

Privacy watchdogs are now reminding people to carefully consider what they're posting online, urging them to take steps to limit how much of their personal information is gathered.

"You should always think about how much information you're sharing," Jennifer Stoddart, Canada's privacy commissioner, told CTV's Power Play on Wednesday.

Stoddard was on the show to discuss the federal government's efforts to educate Canadians -- particularly kids and their parents -- about online safety ahead of Thursday's international Data Privacy Day.

"People are incredibly reckless in putting things out on the Internet, in my point of view," she said. "And the problem is, these things are coming back to haunt them increasingly."

Beginning March 1, Google will have a much better idea of what you do online, who you're in contact with and what kind of photos, videos and other media you're sharing with family and friends.

The company has announced it will begin linking user data across its email, video and social networking services to get a better profile of its users and allow advertisers to target specific consumers.

"If you're signed into Google, we can do things like suggest search queries -- or tailor your search results -- based on the interests you've expressed in Google (Plus), Gmail and YouTube," the company says on a new overview page for its privacy policies.

For example, if you look up "Audi" in the Google search engine while logged into Gmail, you may see an ad for the latest Audi vehicle scroll above your inbox.

Or, if you've had a heated discussion about Lana Del Ray with a friend via Gmail chat, YouTube will suggest you watch some of the controversial singer's latest videos the next time you log on to the site.

Stoddard said the so-called "behavioural advertising" -- tailoring ads to Internet users based on their online searches and website visits -- is a big concern.

"It does creep a lot of people out," she said, noting that her office released online advertising guidelines in December, warning companies that it's against Canada's privacy laws to track people from site to site without their consent.

"We're working with the industry," Stoddard said. "Of course, implementing (the guidelines) is a challenge."

Google has always collected some information on its users, but this will be the first time it combines data from different platforms to get a more nuanced profile of an individual's online habits.

The changes do not apply to Google Chrome web browser, Google Books and Google Wallet, which remain under separate privacy rules.

Critics have lambasted Google for not giving users the choice to opt out of the new policy.

For those who don't like it and want to close their Google accounts, the company's engineers have created something called the Data Liberation Front, which allows users to export personal information from Google services and take it elsewhere.

Others can limit Google's tracking by ensuring they're logged out of Gmail, YouTube, Picasa and other sites while using the search engine.

Google and the Federal Trade Commission reached a settlement last year that forbids Google from misrepresenting how it uses personal information and from sharing an individual's data without prior approval. Google also agreed to biennial privacy audits for the next two decades.

With files from The Associated Press